Fan.



w. K. LIGGETT.

FAN.

APPLICATION FILED AUG-7| I913.

Patented Oct. 16, 1917.

Witnesses UNITED STATES ra'rau WILLIAM K. LIGGETT, F COLUMBUS, OHIO, ASSIGNOR TO THE JEFFREY MANUFAC- TUBING COMPANY, OF COLUMBUS, OHIO, A CORPORATION OF OHIO.

FAN.

Specification of Letters Patent.

Patented Oct. 16, 1917.

Application filed August 7, 1913. Serial No. 783,567.

To all Whom. it may concern Be it known-that I, WILLIAM K. Lrccnrr, a citizen of the United States, residing at Columbus, in the county of Franklin and State of Ohio, have invented certain new and useful Improvements in Fans, of which the following is a specification, reference being bad therein to the accompanying drawing.

This invention relates to improvements in centrifugal fans, and in particular to that class of fans such as are used for ventilating mines. The fan runner comprises in general a hub carrying a circular plate around the periphery of which are spaced a series of wings and blades secured together at their opposite ends by an annular ring. The fan as illustrated is of the single inlet form though it is obvious that the same arrangement of blades is equally advantageous when used in connection with a double inlet fan.

Among the objects of my invention is the construction of a fan of great efficiency handling large volumes of air under sufficient pressure to insure the proper ventilation of the devious passage ways of a mine. Another object is to construct a ventilating fan of great capacity at the same time keeping down the weight factor.

Of the drawings Figure 1 is a side elevation of my improvide fan with parts broken away;

Fig. 2 is a vertical transverse sectional view on the line 22 of Fig. 1; and

Figs. 3, 4 and 5 are plan views of the wings and vanes before bending.

Referring to the drawings A represents the fan casing which is of the involuble type with a. discharge aperture at B and a central intake opening at C. Preferably a suction pipe D is connected with the opening C to conduct air from a mine or other place to be ventilated. As shown in the drawings, the casing A is formed in part of a concrete pit A, but as to this there can be variations, as the details of the casing itself form no part of my present in vention. The fan rotor or runner is mounted in the casing in the usual way and the numeral 1 indicates a fan shaft driven from some suitable power by means of the belt wheel 1 and journaled in a bearing 2. Upon the projecting end of this shaft is keyed a hub 8 which flares out at one end forming a circular plate 4. One side of the plate a is planed oif and carries a large circular sheet or disk 5 which extends outward to the periphery of the fan. The disk 5 is secured by bolts or rivets upon the plate 4.

A series of wings and blades formed. as illustrated in Figs. 3, 4 and 5 then bent or curved to conform to arcs of circles of equal diameter are riveted at one end around the periphery of the disk 5.

The arrangement of the blades and wings is best illustrated in Fig. 1. The blades and wings are so arranged that the centers of the circles of which they form arcs all lie in the circumference of a circle indicated by the numeral 6 described about the center of the fan. In the particular type of fan illustrated there are eight main wings 7 equally spaced around the periphery of the fan. Positioned midway between the main wings 7 are wings 8 somewhat shorter than the wings 7. Each subdivision of the periphery formed between the wings 7 and 8 contains two blades 9 and 10 spaced equally between the blades 7 and 8 and of a length approximately half that of the blade 8. As already stated the radii about which each of the blades and wings are described are equal, and in Fig. 1 are indicated by the letter a.

The ends of the wings and blades opposite the ends riveted to the disk 5 are secured to a narrow ring 11 which is comparatively narrow and shrouds only the outer ends of the wings and blades. An L-shaped ring 12 is riveted to the inner edge of the ring 11 reinforcing the structure and providing an inlet or eye for the fan. All 0 the wings and blades extend into the eye of the fan, the larger of the wings 7 extending approximately half way to the center. To further strengthen and stiifen the structure I have provided a series of stay rods 13 which are bolted at their outer ends to the inner edge of the ring 11. The stay rods extend radially inward, at the same time converging axially inward and are secured by means of the bolts 14 to the outer face of the hub 3.

By arranging the blades and plates in the manner described I provide a fan which has a remarkably high efiiciency and handles a large volume of air. The fan while ordinarily used for inducing a current of air it into the atmosphere is equally efiective as a blower fan for forcin a large volume of air into the ventilating s aft of a mine. The structure of the fan is arranged So that it is perfectly rigid when constructed in large sizes of eighteen to twenty feet in diameter.

What I claim is:

1. In a centrifugal fan, the combination with a casing, of a rotatable imperforate plane sheet metal disk, a narrow rotatable plane sheet metal ring parallel to and spaced from the disk and having the same outer diameter, andclosely arranged sheet metalblades concaved in the direction of rotation and extending between and secured to the said disk and ring, the blades being formed from metal sheets having varying lengths at the sides secured to the disk and having equal lengths at the sides secured to the ring substantially the same as the width of the ring.

2. In a centrifugal fan, the combination in the direction of rotation and extending between and secured to the said disk and ring, the blades bein formed from metal sheets having varying engths at the sides secured to the disk and having equal lengths at the opposite sides substantially the same as the Width of the ring, and braces extending inward from the ring to points near the center of the disk.

In testimony whereof, I aflix my signature, in presence of two witnesses.

WILLIAM K. LIGGETT. Witnesses:

DUDLEY T. FISHER, E. L. HOPKINS. 

